1. Field of the Invention
The present invention relates to the technical field of down lamps, and more particularly to the LED down lamp with a replaceable color temperature filter capable of achieving the effects of enhancing the applicability of the down lamp and assisting wholesales of illumination equipment to reduce inventory.
2. Description of the Related Art
After light-Emitting Diodes (LED) hit the illumination market with the features of low power consumption and high performance, one of the major research and development issues for related manufacturers is to control the luminance, brightness and service life of LED illumination equipments, and the LED illumination equipments are generally divided into two main types, respectively: a detachable lamp with a replaceable LED bulb or tube and an integrally formed lamp integrated with an LED light source, a lamp holder and a heat sink (might be directly combined with the lamp holder). The detachable lamp allows users to change flexibly various LED light source in different color temperatures to provide a wider scope of applicability and a better economic benefit of replacing damaged LED light sources. However, such LED lamp has a poor heat dissipation effect, thus causing a low performance of the LED lamp as well as affecting the brightness of the emitted light, the stability of the illumination and the service life of the product. On the other hand, the integrally formed LED lamp has a better heat dissipation effect, but the finished goods do not allow users to change the light color flexibly. For example, a down lamp generally comes with a color temperature filter attached onto a light projecting surface or comes with a given color temperature LED light source, so that the lamp projects light and four single color tone only, thus limiting the scope of applicability and requiring a large inventory.
To meet the requirements of the color tone of illuminations in different occasions, the conventional LED lamps adopt a control circuit to control the LED light source of various color lights and adjust the light intensity of the LED light source of various different color lights in order to change the color tone projected from the lamps. However, such method incurs a very complicated circuit and a very high cost. Alternatively, Yttrium Aluminum Garnet (YAG) fluorescent powder is coated onto the blue LED light source, wherein the fluorescent powder produces a mixed yellow and green light of 500˜560 nm to produce a white light. However, such method still cannot overcomes the drawbacks including the need of changing the color temperature of an integrally formed lamp such as the down lamp, the low light uniformity, and the easily deviated color temperature that may affect the consistence of the color tone and the color rendering property.
In view of the aforementioned drawbacks, it is a subject for the present invention to improve the down lamp structure to allow users to replace the color temperature filter on their own for flexibly changing the projected color tone, further reducing the inventory cost of the lamps.